Poor aftersales service

I purchased a CCTV Kit online from Makro. Unfortunately, the Power Supply Unit (PSU) has stopped working after 1 month. I filled in the online REPAIR / RETURN request, but 2 days later, I receive a waybill and email from Makro - they wanted to collect it the same day! The CCTV is installed - i.e. cables (that were shipped in 2x 100m rolls) have been fitted all along my property (bolted to walls and running through ceilings, etc.)...and CCTV cameras fixed to the building - which took 2 days to get installed. They expected me to disconnect and packup the entire system into a box and return! I had a spare power supply, connected it - the system is up and running perfectly, so I know exactly which part is faulty. Makro's online team insist that I pack up the entire kit and send it back that day or cancel my return as it has to be returned to a 3rd party to get tested. They said I could not just return the PSU. Sigh. I cancelled the return. Makro should at the very least offer me a partial refund to purchase a replacement PSU.